V2Rocket

do us all a favor next time you run it up that high and aim for a large pothole or rock








out

Julian Allen

The 968 turbo S/RS cars had different half shafts (larger diameter by a few mm) with larger CV's on the inboard and outboard--like a 911 turbo or 928. The transmission output flanges were larger (but NLA). If you end up wanting these (after the straight cut gears and so on) I have some of these size flanges made for me by Quaife.

MPD47

How's your invisible supercharger coming?

Or the fact that you can't keep track of the oil in your engine?

INURGRL951

I had heard roomers of a carbon fiber axle shafts but I do not know if that went anywhere( three years ago). I have only messed up the original shafts the new ones I got 4 years ago have handled plenty of abuse and you don't want to make everything "strengthened" You have to have a "weak" spot that will give. Trust me when you try to make everything stronger the most expensive part seams to be the one to give so I leave certain areas to give where the cost or time will not be so overwhelming you can't keep your car from breaking if you "enjoy" yourself at the wheel...

DANNiE

Woah..! Didnt mean to start a war...

I just want better highway mileage... I live in south florida and I-95 is a nice bit of stretch not that i need to go 200mph at all i just like the idea of doing 75 @ 3K RPM...

But in actuality IF

"the 951 5th is a .829 and the 944 5th is a .730"

the older transmission does actually have a smaller 5th gear ratio then it would in fact give me better RPM to MPH for GPH savings... LoL

So "IF" the early N/A 5th Gear is that size it seems that it would be the ideal 5th gear to have forged and Straight or Helical cut as copys for sale since it would fit right in all the 5-speed trannys...

FYI: I did a lil bit of internet searching and found this excel file where you can plug in your tire/wheel size and it will adjust the ratios and Numbers...

http://www.924.org/Downloads/PorscheTrans1.xls

Turns out NO stock ratio will yield 200mph the most i could get using stock 944 parts and my current rims on my 90 S2 is 155MPH... Id need a 3.375 Final Drive & a .730 5th... and even with a .600 5th gear from a 924/931 only 188MPH is obtained...

These numbers sound more realistic; just my mechanic side thinking with the "math" in mind too...

Duke

Nice, but I'm afraid of asking how much $$$ that was..

JohnKoaWood

My 87 951 turns 3K at 80 MPH... maybe 2800 at 75...

CurtP

I'm not afraid.

How much were those puppies? Damn those are nice.

Julian Allen

More than $5 . . .

Julian Allen

Seriously, this sort of one-off machine shop work is expensive per unit unless you get into making a few hundred. The market for these (real market, not the oh boy I'd put them on if they were $25) is kind of rarefied, so I doubt you could sell many. Mine are for the 968 transmission, but they can be made for the 944 series I'm sure.
Figure $5-600 each if you want them made. Paul Guard, Quaife, and others can make them. If you're really going to the expense of making straight cut gears for the transmissions, that's probably not a large incremental cost.

JohnKoaWood

If putting down real power, the straight cut gear set and a set of beefed up flanges / CV shafts is a nice little addition...

Considering a properly done, completed 3L+ turbo engine can easily run over 20K another 5-10K into a solid power relay setup to put it to the ground is a good decision, and should help with reliability.. the ability to customize the gear ratios would greatly help with drivability...

not to mention if you jump to a 968 6 speed you gain even more ability to spread the ratios and make maximum use of all the new found torque and power... reliably...

Do you have a drawing set for these, or did Quaife keep that?

DANNiE

My S2 doesnt have the same final drive as your 951 and considering the gear ratio #'s are right from the excel sheet my fifth gear is shorter too...

JohnKoaWood

ATASO... S2ida...

maybe swap a 951 gearbox into your S2? Just kidding...

there is a whole world of options available, you just have to think in the broader terms of Audi 5000-016 gearbox rather than Porsche 944 series gearbox... even consider an Audi 01E gearbox...

http://forums.audiworld.com/showthread.php?t=1971017

http://www.kitcentral.com/index.php?...wtopic&p=24319

Audi actualy like the gearbox design a lot... they used it in several different cars, Audi 5000 not withstanding... and they used a whole range of gear ratios over the years, which I understand can be interchanged...

BUT... they will all fail at the same power levels (400 ish HP, rough driven) and no matter how careful you drive them they WILL all eventualy fail over 400HP..

Straight cut them, add a nice beefy shaft and now your talking.. those norwegans are putting some serious HP (1000+) into gearboxes that are cousins of the gearboxes we are running...

<<<PURE SEX CONTENT>>>


but the conversion rate makes this a 6 speed gearset (for an Audi 01E box) worth more than most 968s... roughly 16K based on conversion rate.. and they don't even make any mention of the R&P... Hmmm wonder what they are doing there.... hmmmm

gt37vgt

so do you think it would last longer than the 6 trans axles i would buy with my 16000???

JohnKoaWood

Costas has said he is on his same gear box in a second car... but 16K is an insane price to pay.. I am sure they are not realizing volume at 16K.. at 6K maybe.. at 2K they would be flying off the shelf...

How many transaxles are there left that will one day cause the cost to become prohibitive?

same could be said for a big displacement motor to get 400HP... it can be done smaller, but how long would it last?